The present application relates to semiconductor technology, and more particularly to a semiconductor structure containing a FinFET device having an improved stressor structure in the source/drain regions in which defects within the stressor structure are not present near the device channel. The present application also provides a method of forming such a semiconductor structure.
For more than three decades, the continued miniaturization of metal oxide semiconductor field effect transistors (MOSFETs) has driven the worldwide semiconductor industry. Various showstoppers to continued scaling have been predicated for decades, but a history of innovation has sustained Moore's Law in spite of many challenges. However, there are growing signs today that metal oxide semiconductor transistors are beginning to reach their traditional scaling limits. Since it has become increasingly difficult to improve MOSFETs and therefore complementary metal oxide semiconductor (CMOS) performance through continued scaling, further methods for improving performance in addition to scaling have become critical.
The use of non-planar semiconductor devices such as, for example, silicon fin field effect transistors (FinFETs) is the next step in the evolution of complementary metal oxide semiconductor (CMOS) devices. Fin field effect transistors (FinFETs) can achieve higher drive currents with increasingly smaller dimensions as compared to conventional planar FETs.
In the prior art, the formation of an embedded stressor within a semiconductor-on-insulator (SOI) FinFET starting from the substrate has been proposed to increase the volume of the embedded stressor. However, one concern with such an approach is that when the embedded stressor is epitaxially grown from the substrate, the epitaxial growth fronts meet with the channel material that is present near the gate spacer.
It is also known to grown the stressor material from both ends of a semiconductor fin as well as the substrate such that the epitaxy front ends up in the middle of the source/drain region. However, control of such a process is difficult to achieve.